O yeah sorry, forgot about that 
I don't know how the 3850 performs, have a rough idea, but never looked at any expert reviews, however for my GPU, when I was doing reviews a few months after its release, iirc it beat the 8800GT by a good bit, for crysis iirc the difference was something like 10-15 FPS and it was different for each resolution and some other games it was a bit more iirc. When I say cards of similar performance, I mean within like 5 FPS for nearly every game, not just 1 or 2 games.
But my 4850 back then was the best 4850 you could buy for the money, won so many awards on nearly every well known expert review site iirc. So if it was just a stock ATI 4850 then yeah I agree, that the minimum for ATI should be a 4850 512MB card.
Personally IMO, HIS are the best brand you can buy for the ATI cards, don't know what the best brand for nvidia is as it has been a while since I last used one of their cards or did any research for there latest ones
Hope I explained that a bit better

I don't know how the 3850 performs, have a rough idea, but never looked at any expert reviews, however for my GPU, when I was doing reviews a few months after its release, iirc it beat the 8800GT by a good bit, for crysis iirc the difference was something like 10-15 FPS and it was different for each resolution and some other games it was a bit more iirc. When I say cards of similar performance, I mean within like 5 FPS for nearly every game, not just 1 or 2 games.
But my 4850 back then was the best 4850 you could buy for the money, won so many awards on nearly every well known expert review site iirc. So if it was just a stock ATI 4850 then yeah I agree, that the minimum for ATI should be a 4850 512MB card.
Personally IMO, HIS are the best brand you can buy for the ATI cards, don't know what the best brand for nvidia is as it has been a while since I last used one of their cards or did any research for there latest ones

Hope I explained that a bit better
